John Stewart, who wrote the Monkees hit Daydream Believer and was a member of folk group The Kingston Trio, has died.
John Stewart wrote Daydream Believer in 1967
The 68-year-old suffered a massive stroke or brain aneurysm in San Diego on Friday, according to The Kingston Trio's website.
Stewart joined the group, one of the most successful and influential groups in popular folk, in 1961.
He wrote Daydream Believer, a global hit for The Monkees, in 1967, the same year he left The Kingston Trio.
He went on to record more than 45 solo albums and his biggest solo success came with a US top five single, Gold, in 1979.
Stewart had been told in recent years he was in the early stages of Alzheimer's disease and had suffered numerous minor strokes, his friend Tom DeLisle wrote on The Kingston Trio site.
He collapsed in his hotel room and doctors said any surgery to save his life, if successful, would have left him immobile and unable to speak.
"John Stewart leaves a compilation of musical excellence unparalleled in his time," Mr DeLisle wrote.
"He leaves behind a wide-ranging group of fans who have felt a passion for him and his music that bordered on fanaticism."